(DURHAM) -- A 20 year study at Duke University suggests that bullies are not as harmless as they might seem. Duke University Associate Professor of Psychiatry Dr. William Copeland said victims of bullying had higher levels of C-reactive proteins in adulthood.

Researchers looked at levels of C-reactive protein which is a marker for inflammation and is associated with cardiovascular disease and metabolic syndrome.

"There are programs out there that we know can be effective if they are implemented widely, broadly and school systems are willing to invest in these things and get teachers, administration, parents, and kids on board," Copeland said.

Bullying is not just a rite of passage and anti-bullying programs are important, Copeland said.

Copeland said researchers also followed up with the bullies. They were seen to have the lowest levels of C-reactive protein of any other group, which is a health advantage.

"This is an experience of social humiliation which is often a chronic sort of experience and over time this can really lead to deregulation in certain stress response systems which can be associated with increases in levels of inflammation," Copeland said.